Commit Graph

9 Commits

Author SHA1 Message Date
Richard Trieu bb43dec255 Remove warning for conditional operands of differend signedness from -Wsign-compare. Cases that previously warn on this will have a different warning emitted from -Wsign-conversion.
llvm-svn: 135664
2011-07-21 02:46:28 +00:00
Douglas Gregor 5b05454f24 Don't produce "comparison is always (true|false)" warnings when the
comparison itself is a constant expression. Fixes PR7536.

llvm-svn: 126057
2011-02-19 22:34:59 +00:00
Douglas Gregor f267edd8ac Update equality and relationship comparisons of pointers to reflect
C++ semantics, eliminating an extension diagnostic that doesn't match
C++ semantics (ordered comparison with NULL) and tightening some
extwarns to errors in C++ to match GCC and maintain conformance in
SFINAE contexts. Fixes <rdar://problem/7941392>.

llvm-svn: 106050
2010-06-15 21:38:40 +00:00
John McCall cc7e5bff5c Rearchitect -Wconversion and -Wsign-compare. Instead of computing them
"bottom-up" when implicit casts and comparisons are inserted, compute them
"top-down" when the full expression is finished.  Makes it easier to
coordinate warnings and thus implement -Wconversion for signedness
conversions without double-warning with -Wsign-compare.  Also makes it possible
to realize that a signedness conversion is okay because the context is
performing the inverse conversion.  Also simplifies some logic that was
trying to calculate the ultimate comparison/result type and getting it wrong.
Also fixes a problem with the C++ explicit casts which are often "implemented"
in the AST with a series of implicit cast expressions.

llvm-svn: 103174
2010-05-06 08:58:33 +00:00
Daniel Dunbar 8fbe78f6fc Update tests to use %clang_cc1 instead of 'clang-cc' or 'clang -cc1'.
- This is designed to make it obvious that %clang_cc1 is a "test variable"
   which is substituted. It is '%clang_cc1' instead of '%clang -cc1' because it
   can be useful to redefine what gets run as 'clang -cc1' (for example, to set
   a default target).

llvm-svn: 91446
2009-12-15 20:14:24 +00:00
John McCall 5677499fbf First pass at implementing C++ enum semantics: calculate (and store) an
"integer promotion" type associated with an enum decl, and use this type to
determine which type to promote to.  This type obeys C++ [conv.prom]p2 and
is therefore generally signed unless the range of the enumerators forces
it to be unsigned.

Kills off a lot of false positives from -Wsign-compare in C++, addressing
rdar://7455616

llvm-svn: 90965
2009-12-09 09:09:27 +00:00
John McCall 99ce6bfe28 Improve the -Wsign-compare heuristics:
* If the unsigned type is smaller than the signed type, never warn, because
    its value will not change when zero-extended to the larger type.
  * If we're testing for (in)equality, and the unsigned value is an integer
    constant whose sign bit is not set, never warn, because even though the
    signed value might change, it can't affect the result of the equality.

Also make the comparison test cases much more rigorous, and have them expose
the subtle differences between C and C++ here.

llvm-svn: 86242
2009-11-06 08:49:08 +00:00
Douglas Gregor 6af6c3ee56 Turn off -Wsign-compare warnings by default
llvm-svn: 86233
2009-11-06 05:24:12 +00:00
John McCall 1fa36b7cab Implement the conditional-operator part of -Wsign-compare. Turn
DiagnoseSignCompare into Sema::CheckSignCompare and call it from more places.

Add some enumerator tests.  These seem to expose some oddities in the
types we're converting C++ enumerators to;  in particular, they're converting
to unsigned before int, which seems to contradict 4.5 [conv.prom] p2.

Note to self: stop baiting Doug in my commit messages.

llvm-svn: 86128
2009-11-05 09:23:39 +00:00